test build for cardputer only (outdated)

flash with esptool.py write_flash 0x10000 m5stack-cardputer-firmware.bin.

Differences with mainline:

• added ir, rf, music_player, say, led, power, clock serial commands (pr3y#64)
• added "Custom Subghz" in RF menu (only for 433mhz ASK/OOK, RAW mode still untested)
• added main menu keyboard shortcuts to quickly launch some apps (pr3y#64 (comment))
• serial commands processor running on a separate core (pr3y#64 (comment))